Centrifugal air cleaner



July 17,. 1951 F. KELSO CENTRIFUGAL AIR CLEANER 2 Sheets-Sheet 2 FiledApril 6. 1950 Patented July 17, 1951 UNITED STATES PATENT OFFICECENT'R'IFUGAL AIR CLEANER Frank Kelso, ;Fort William, Ontario, CanadaApplication April 6, 1950, Serial N 0. 154,211

4:;Claims. 1

My invention relates to air cleaners and, more particularly, to aircleaners of the centrifugal type.

More specifically, my invention relates to improvements inmechanically-driven air cleaners as distinguished from the well-knowncyclone type in which a swirling motion is imparted to the air in ashell by means of introducing the same into the shell tangentially andunder pressure.

The primary object of my invention is to provide a structure which is ofthe class above-described, and which is more efficient than structures.of this type heretofore produced.

A further object of my invention is the pro- Fig. 2 is an enlarged view,partly in plan and a partly in horizontal section, taken on the line22'of Fig. 1, some parts being broken awayj Fig. 3 is a vertically axialsection, taken on the line 3-3 of Fig. 2; and

Fig. 4 is a view in perspective of my novel air cleaner, some partsbeing broken away and some parts being shown in section.

My novel air cleaner comprises spaced upper and lower wall-formingelements I and 2 respectively which define an expansion chamber 3. Theupper wall-forming element I is for the most part fiat and, at itsperipheral portion, is downwardly dished as indicated at 4, convergingwith the lower wall-forming element 2, which is preferably conical inshape. The peripheral edges of the wall-forming elements I and 2 arespaced apart to provide a restricted peripheral dust passage 5. Acentral outlet 6 in the wall-forming element I is axially-aligned withan inlet I in the wall-forming element '2. An imperforate circularbaflie plate 8 divides the chamber 3 into inlet .and outlet compartments9 and I respectively, the former communicating with the inlet 1 and thelatter communicating with the outlet 6. The baflle plate 8 liessubstantially in the plane of the peripheral dust passage .5 and is ofsmaller diameter than the wall-forming plates 1 and 2, the space betweenthe peripheral edges of the baille plate and the peripheral edges of thewall-forming elements I and 2 providing an annular gas passage II.

A plurality of circumferentially-spaced radially-projecting imperforatevanes I2 are radially disposed Within the inlet compartment 9 and extendfrom the inlet 1 thereof to the .peripheral edge of the baffle plate 8.A plurality of sirnilarl spaced imperforate vanes I3 areradially-disposed within the outlet compartment I0 and extend outwardlyfrom the outlet 6 to the periphery edge of the wall-forming element I,The vanes I2 and I3 are rigidly secured at their opposite side edges tothe bafile plate 8 and their respective wall-forming elements I and 2.With reference to Figs. 2,, 3, and 4, it will be seen that the vanes I3are equal in number to the vanes I 2, .one each of the vanes I3overlying one of the vanes I2.

An annular generally conical baffle plate III is located within theoutlet compartment .II'I concentric with the outlet 6, and has its innerportion rigidly secured'by welding or the like to the baffle plate 8,its outer peripheral edge being in relatively closely spacedrelationship to the wallforming element I, whereby to provide arestricted gas or air passage I5 therebetween. It will be noted that thebaffle plate I4 is of less diameter than the baflie plate 8. The vanesI3 may be slotted to receive the conical baffle plate I4, or said baffleplate I4 may be made in sections, each extending between adjacent vanesI3. In any event, the conical baflle plate It is rigidly secured to eachof the vanes I3 by welding or the like.

My improved air cleaner is adapted to be mounted for rotation within adownwardly-tapered conical housing or the like I6, the axis of which isconcentric to the axis of the cleaners. The housing I6 is provided witha relatively flat top wall I-I and a downwardly-opening dust-dischargeoutlet I8 at its apex portion. A conduit I6 extends through and issupported by the tapered side wall of the housing I6 and terminateswithin the inlet 1 of the air cleaner. The conduit I 9 extends to and isadapted to conduct dustladen air from a desired room or area, not shown.A second conduit 20 extends axially through the top wall H of thehousing I6 and is supported thereby as indicated at 2 I. The conduit 20is bent to form an elbow portion 22 and is adapted to extend to and becoupled with the intake of a blower not shown, whereby dust-laden airmay be drawn through the conduit I9, the expansion chamber 3, and theconduit 20. The intake end of the conduit 20 is enlarged, as indicatedat 20', and encompasses the outlet 6 of the wall-forming element Isufiiciently loosely to permit free rotation of the wall-forming elementI with respect to the conduit 20.

A rotary shaft 23 is axially aligned with the wall-forming elements Iand 2 and has its lower end rigidly secured by Welding or the liketo'the center of the baflle plate 8, as indicated at 24. The shaftextends axially upwardly through the outlet 6 and the lower portion ofthe conduit 29, and through the wall of the elbow portion 22, where itis journalled in a bearing 25. It will be noted that the air cleanerstructure, including the wall-forming elements I and 2, depend from theshaft 23 and are supported against downward movement with respect to theconduits I9 and 20 and the housing I6 by a collar 26 pinned or otherwiserigidly secured to the upper end portion of the shaft 23 and engagingthe outer end of the bearing 25. The shaft 23 is further journalled in abearing 2'1 rigidly mounted in the lower end portion of the conduit 20by means of a conventional spider mounting or the like 23. Rotarymovement is applied to the shaft 23 and the air cleaner supportedthereby from a motor or other rotary 'element not shown but adapted tobe connected to the shaft 23 by a V-belt or the like 29 running over apulley 3i! rigidly secured to the 'upper end of the shaft 23.

When it is desired to utilize my novel air cleaner to remove dust from aparticular area, the air is caused to be drawn through the conduits I9and 2B and the expansion chamber 3 of the air cleaner by the blower, notshown. Simultaneously, the cleaner is caused to rotate on the axis oftheshaft 23. As the dust-laden air enters the expansion chamber, itsvelocity is appreciably decreased. However, rotation of the cleanercauses the dust in the air to impinge upon the vanes I2 of the inletcompartment and be discharged radially outwardly through the restrictedperipheral passage 5 by the action of centrifugal force, together with arelatively small amount of air. The bulk of the air drawn into the inletcompartment 9 is drawn upwardly through the annular gas passage II intothe outlet compartment H] and radially inwardly through the restrictedpassage I5 to the outlet 6 and upwardly through the conduit 20. Theconical bafiie plate I4, due to its inclination toward the wall-formingelement I, tends to set up eddy currents in the air travelling radiallyinwardly from the annular passages II. Any

'residual dust failing to escape through the peripheral dust passage 5and being carried upwardly through the annular passage H is caught inthe eddy currents below the peripheral edge portion of the baffle plateI4, as shown by broken arrows in Fig. 3, and impinges against therotating vanes I3 and is thrown radially outwardly.

by centrifugal force through the air stream flowing upwardly through theannular passage II and through the peripheral dust passage 5 into thehousing I6. The eddy currents extract substantially all the remainingdust in the air fiow-' ing through the compartment In, so thatrelatively dust-free air is drawn inwardly through the restrictedpassage I5, the outlet 6, and the conduit 20. Obviously, the suction ofthe blower is sufiicient to maintain a continual flow,

of air upwardly through the air cleaner to overcome the tendency of theair to be blown outwardly through the peripheral dust passage 5.However, the speed of rotation of the shaft 23 and the baffles, vanes,and wall-forming elements carried thereby, is such that the dustparticles are discharged radially through the peripheral dust passage 5and the air is permitted to be drawn radially inwardly through thecompartment I0 and restricted passage I5 against the action ofcentrifugal force.

My improved cleaner has been thoroughly tested and found to becompletely satisfactory for the accomplishment of the objectives setforth; and, while I have shown and described a commercial embodiment ofmy rotary air cleaner, it will be understood that the same is capable ofmodification without departure from the spirit and scope of theinvention as defined in the claims.

What I claim is:

1. In a device of the class described, upper and lower wall-formingelements defining an expansion chamber, said elements having alignedcentral inlet and outlet openings one in each thereof, said wall-formingelements converging toward their peripheral edges, said peripheral edgesbeing spaced apart to provide a restricted peripheral dust passage, animperforate baflle plate within said chamber, said bafiie plate be ingin substantially the same plane as the restricted dust passage anddividing said chamber into inlet and outlet compartments, said baffleplate terminating radially inwardly of said restricted dust passagewhereby to provide an annular gas passage between said inlet and outletcompartments, a plurality of circumferentially-spacedradially-projecting imperforate vanes in each of said compartments, anannular generally conical baflie plate in the outlet compartment, saidlast-mentioned baffle plate being 'secured at its inner portion to saidfirst-mentioned baiile plate and terminating at its peripheral edgeintermediate said first-mentioned bafile plate and the adjacentwall-forming element, the outer diameter of said last-mentioned bafileplate being less than the diameter of said first-mentioned bafiie plate,and means for simultaneously rotating said wall-forming elements saidbaiile plates and said vanes as a unit about the axis of said inlet andoutlet openings.

2. The structure defined in claim 1 in which said outlet compartmentoverlies said inlet compartment and in which said last-mentioned baffieplate is concentric with said inlet and outlet openings.

3. The structure defined in claim 1 in which the vanes in the inletcompartment extend. from the inlet opening to the peripheral edge of thefirst-mentioned baflle plate and in which the vanes in the outletcompartment extend from the outlet opening to the peripheral edge of theadjacent upper wall-forming element.

4. The structure defined in claim 1 in further combination with anon-rotary housing encompassing said wall-forming elements, said housingterminating at its lower endin a dust discharge opening concentric withthe inlet and outlet openings of the expansion chamber, a non-rotaryelbow-shaped conduit projecting through the wall and a bearing centrallymounted in said lastmentioned elbow adjacent said outlet, said means forsimultaneously rotating said wall-forming elements including a driveshaft journalled in said bearing, said drive shaft having its inner endrigidly secured to the central portion of said first-mentioned bafiieplate and its outer end projecting through its cooperating elbow, anddriving connections on said. shaft outwardly of said elbow.

FRANK KELSO.

REFERENCES CITED The following references are of record in the file ofthis patent:

Number 39 Number 6 '1 UNITED STATES PATENTS Name Date Kelley et a1. May6, 1919 Thompson Feb. 27, 1923 Jett Aug. 19, 1924 Aalborg Feb. 19, 1929Dodge Dec. 5, 1944 FOREIGN PATENTS Country Date Great Britain Nov. 5,1940

